Refrigerating cycle and component assembly for the same

ABSTRACT

A refrigerating cycle has a compressor, a high pressure heat exchanger, a decompressing device, a low pressure heat exchanger and a low pressure refrigerant passage part that defines a passage through which a low pressure refrigerant after being decompressed by the decompressing device flows. The low pressure refrigerant passage part is disposed at a position upstream of the high pressure heat exchanger with respect to a flow of cooling fluid such that the cooling fluid is introduced toward the high pressure heat exchanger after being cooled by the low pressure refrigerant passage part. For example, the low pressure refrigerant passage part includes an internal heat exchanger and a metal portion of a hose that introduces the low pressure refrigerant toward the compressor. Also, the internal heat exchanger and the high pressure heat exchanger are integrated into a unit as a component assembly before being mounted to an object.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on Japanese Patent Application No. 2006-133076 filed on May 11, 2006, the disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a refrigerating cycle and a component assembly for the refrigerating cycle.

BACKGROUND OF THE INVENTION

A refrigerating cycle for a vehicle air conditioner generally includes a compressor 10, a radiator (e.g., condenser, gas cooler) 100 as a high pressure-side heat exchanger, a decompressing device 300, an evaporator 400, a gas-liquid separator 500, and an internal heat exchanger 200, as shown in FIG. 7. The preceding components are for example connected through refrigerant pipes P1 to P5 and refrigerant hoses H1, H2, as shown in FIG. 8. The radiator 100 is disposed in front of a radiator 600 in an engine compartment EC of a vehicle to receive air (arrow A1) while the vehicle is running for cooling a refrigerant flowing therein. Also, in FIG. 8, components that are substantially the same as components which will be described later are designated by the same reference numerals and a description thereof is omitted.

Regarding such a refrigerating cycle, Japanese Unexamined Patent Publication No. 2004-239479 discloses an arrangement of a radiator so as to improve cooling efficiency of a refrigerant. The radiator is constructed such that a refrigerant inlet portion is disposed adjacent to an area where temperature of cooling air is high in temperature distribution of the cooling air and a refrigerant outlet portion is disposed adjacent to an area where temperature of the cooling air is low in the temperature distribution.

However, the temperature distribution of the cooling air is different depending on vehicles. Even in the vehicles of the same model, the temperature distribution of the cooling air is likely to be varied by types or arrangement of components such as an engine, a radiator, a cooling fan, an inter cooler, a grill and the like. Also, positions of the refrigerant inlet and outlet portions of the radiator are likely to be limited due to various factors such as a space in an engine compartment, arrangement compatibility between different systems (e.g. a supercritical cycle using carbon dioxide as a refrigerant and a subcritical cycle using chlorofluorocarbon as a refrigerant.)

Also, in the refrigerating cycle having the internal heat exchanger, the number of parts and the number of coupling portions of pipes increase. Therefore, the number of assembling steps increase.

SUMMARY OF THE INVENTION

The present invention is made in view of the foregoing matter, and it is an object of the present invention to provide a refrigerating cycle and a component assembly for the refrigerating cycle, capable of stably cooling a refrigerant in a high pressure heat exchanger.

It is another object of the present invention to provide a refrigerating cycle and a component assembly for the refrigerating cycle, capable of improving assemblability.

It is further another object of the present invention to provide a refrigerating cycle and a component assembly for the refrigerating cycle, capable of improving mountability to an object such as a vehicle.

According to an aspect of the present invention, a refrigerating cycle has a compressor for sucking and compressing a refrigerant, a high pressure heat exchanger for performing heat exchange between a high pressure refrigerant compressed in the compressor and a cooling fluid flowing outside of the high pressure heat exchanger, a decompressing device for decompressing the high pressure refrigerant into a low pressure refrigerant, a low pressure heat exchanger for evaporating the low pressure refrigerant, and a low pressure refrigerant passage part for defining a passage through which the low pressure refrigerant flows. The low pressure refrigerant passage part is disposed at a position upstream of the high pressure heat exchanger such that the cooling fluid is cooled by the low pressure refrigerant passage part before being introduced toward the high pressure heat exchanger.

As such, the cooling fluid that has been cooled by the low pressure refrigerant passage part flows through the high pressure heat exchanger. Therefore, the high pressure refrigerant flowing in the high pressure heat exchanger is stably cooled.

For example, the low pressure refrigerant passage part includes an internal heat exchanger that has a low pressure refrigerant passage through which the low pressure refrigerant flows and a high pressure refrigerant passage for performing heat exchange between the high pressure refrigerant and the low pressure refrigerant. Also, the low pressure refrigerant passage part may includes a metal portion of a refrigerant hose through which the low pressure refrigerant discharged from the internal heat exchanger and flows toward the compressor flows.

According to a second aspect of the present invention, a component assembly for a refrigerating cycle has a high pressure heat exchanger for performing heat exchange between a high pressure refrigerant and a cooling fluid flowing outside of the high pressure heat exchanger, and an internal heat exchanger for performing heat exchange between the high pressure heat exchanger and a low pressure heat exchanger having a pressure lower than that of the high pressure refrigerant. The internal heat exchanger is integrated with the high pressure heat exchanger on a front side of the high pressure heat exchanger, the front side corresponding to an upstream side with respect to a flow of the cooling fluid when in use.

The high pressure heat exchanger is a relatively large component of components of the refrigerating cycle. The internal heat exchanger is integrated with the high pressure heat exchanger before being fixed to an object such as a vehicle body. Thus, at least the high pressure heat exchanger and the internal heat exchanger are constructed compact and handled as a single unit. As such, the high pressure heat exchanger and the internal heat exchanger are easily transported and assembled to the object. Also, since the internal heat exchanger is integrated with the high pressure heat exchanger beforehand, it is easily connected.

Here, the high pressure heat exchanger and the internal heat exchanger are integrated by various ways or means. For example, the high pressure heat exchanger and the internal heat exchanger are fixed to each other by using fixing members such as clamps and screws or by welding. As another example, the high pressure heat exchanger and the internal heat exchanger are integrally provided by sharing portions thereof.

In a case that the component assembly is mounted in an engine compartment of a vehicle, the internal heat exchanger is located upstream of the high pressure heat exchanger with respect to the flow of the cooling fluid, i.e., in front of the high pressure heat exchanger. Therefore, a space on a rear side of the high pressure heat exchanger is effectively used for other purposes. Also, in a case that the component assembly is mounted in front of a radiator, pipes associating with the refrigerating cycle are easily coupled at a front side of the vehicle. Thus, assemblability improves.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which like parts are designated by like reference numbers and in which:

FIG. 1 is a schematic diagram of a refrigerating cycle for a vehicle according to a first embodiment of the present invention;

FIG. 2 is a plan view of a component assembly, which is encompassed by a dashed line in FIG. 1, according to the first embodiment;

FIG. 3 is a plan view of a gas cooler of the refrigerating cycle according to the first embodiment;

FIG. 4 is a partial perspective view of a heat exchanging part of an internal heat exchanger of the refrigerating cycle, partly including a cross-section, according to the first embodiment;

FIG. 5 is a schematic diagram of a refrigerating cycle for a vehicle according to a second embodiment of the present invention;

FIG. 6A is a schematic diagram of a refrigerating cycle for a vehicle according to a third embodiment of the present invention;

FIG. 6B is a schematic diagram of the refrigerating cycle for showing an example of arrangement of a low pressure refrigerant passage part relative to a gas cooler according to the third embodiment;

FIG. 7 is a schematic diagram of a refrigerating cycle mounted to a vehicle as a related art; and

FIG. 8 is a schematic diagram of the refrigerating cycle shown in FIG. 7.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS First Embodiment

A first embodiment will be described with reference to FIGS. 1 to 4. In the first embodiment, a refrigerating cycle is for example employed as a supercritical vapor compression refrigerating cycle for a vehicle air conditioner in which carbon dioxide is used as a refrigerant (heat exchange medium). Alternatively, ethylene, ethane, nitrogen oxide or the like can be used as the refrigerant. Further, when an air conditioning load is high such as in summer, pressure of a high pressure refrigerant discharged from a compressor is increased equal to or higher than a critical pressure to thereby provide predetermined cooling (refrigerating) capacity.

The refrigerating cycle generally includes a compressor 10, a gas cooler 100 as a high pressure-side heat exchanger, a decompressing device 300, an internal heat exchanger 200, an evaporator 400 as a low pressure-side heat exchanger, and an accumulator 500 as a gas-liquid separator. Further, the gas cooler 100, the internal heat exchanger 200, the expansion valve 300 and the like, which are encompassed by a dashed line in FIG. 1, are integrated into a component assembly, as shown in FIG. 2.

Hereafter, the respective components for the refrigerating cycle will be described in line with a flow of the refrigerant. The compressor 10 is driven by an engine of a vehicle. The compressor 10 sucks and compresses the refrigerant. The compressor 10 is connected to the gas cooler 100 through a first refrigerant hose H1 having flexibility so that a high pressure refrigerant compressed in the compressor 10 is introduced to the gas cooler 100.

The gas cooler 100 is arranged so that cooling air (cooling fluid, arrow A1), which is caused while the vehicle is running or by an operation of a cooling fan (not shown), passes through the gas cooler 100. The gas cooler 100 performs heat exchange between the high pressure refrigerant discharged from the compressor 10 and the air, thereby to cool the high pressure refrigerant.

As shown in FIG. 3, the gas cooler 100 generally includes a core part 101 and a pair of header tanks 140 disposed at ends of the core part 101. Components of the gas cooler 100 are for example made of aluminum or aluminum alloy. Predetermined portions of the components are coated with brazing material beforehand. The components are assembled in a predetermined manner such as by engaging, crimping and holding with a jig, and then integrally brazed by the brazing material.

The core part 101 includes tubes 110 defining refrigerant passages therein and fins 120 having corrugated shape, for example. The tubes 110 and the fins 120 are alternately stacked. Thus, the core part 101 mainly performs heat exchange between the refrigerant flowing in the tubes 110 and air passing through the fins 120.

For example, each tube 110 is a flat tube and defines plural refrigerant passages therein extending in a longitudinal direction of the tube 110. The plural refrigerant passages are aligned in a direction in which a width of the tube 110 is measured. Each refrigerant passage has a circular cross-section, for example. Alternatively, the refrigerant passage may have a rectangular cross-section, a triangular cross-section or other cross-sectional shapes.

The tubes 110 are arranged such that flat main walls thereof are parallel to each other at predetermined intervals for allowing the air to flow between the adjacent tubes 110. In the example shown in FIG. 3, the fins 120 are disposed between the tubes 110. However, the fins 120 may be eliminated from the core part 101.

The core part 101 further includes side plates 130 as reinforcing members. The side plates 130 are arranged along the outermost fins 120. Each side plate 130 for example has a U-shaped cross-section.

The header tanks 140 are coupled to longitudinal ends of the tubes 110. The header tanks 140 extend in a direction perpendicular to the longitudinal direction of the tubes, i.e., extend in a stacking direction of the tubes 110. Specifically, each header tank 151 has a passage portion 151 therein for allowing the refrigerant to flow. The longitudinal ends of the tubes 110 are inserted to and joined with the header tanks 140 such that the refrigerant passages of the tubes 110 communicate with the passage portions 151.

The header tanks 140 are provided with end caps 180 to cover ends of the passage portions 151. One of the header tanks 140 (e.g., left header tank 140 in FIG. 3) has a separator 141 such that the passage portion 151 is divided into an upper space and a lower space.

Further, the left header tank 140 has an inlet joint 191 and an outlet joint 192. The inlet joint 191 is brazed at a position higher than the separator 141 as a refrigerant inlet for introducing the refrigerant into the upper space of the passage portion 151. The outlet joint 192 is brazed at a position lower than the separator 141 as a refrigerant outlet for discharging the refrigerant from the lower space of the passage portion 151.

In the gas cooler 100, the refrigerant flows in the upper space of the passage portion 151 from the inlet joint 191 and is distributed into upper tubes 110 that are located higher than the separator 141. After passing through the upper tubes 110, the refrigerant is collected in the opposite header tank 140 (right header tank 140 in FIG. 3) and then distributed into lower tubes 110 that are located lower than the separator 141. After passing through the lower tubes 110, the refrigerant is collected in the lower space of the passage portion 151 of the left header tank 140 and then discharged outside of the gas cooler 100 from the outlet joint 192. As such, while passing through the tubes 110, the refrigerant exchanges heat with the air and radiates heat to the air.

The outlet joint 192 of the gas cooler 100 is connected to a high pressure refrigerant inlet portion 202 of the internal heat exchanger 200 through a first refrigerant pipe P1, which is for example made of metal. Thus, the refrigerant discharged from the gas cooler 100 is introduced into the high pressure refrigerant inlet portion 202 of the internal heat exchanger 200 through the first refrigerant pipe P1. The first refrigerant pipe P1, the gas cooler 100 and the internal heat exchanger 200 are integrated into the component assembly before mounted to a vehicle. The internal heat exchanger 200 is included in a low pressure refrigerant passage part that provides a passage through which the low pressure refrigerant flows at a position upstream of the gas cooler 100 with respect to the flow of the cooling air.

The internal heat exchanger 200 performs heat exchange between the high pressure refrigerant discharged from the gas cooler 100 and a low pressure refrigerant to be sucked into the compressor 10. The internal heat exchanger 200 includes a heat exchanging part 201.

As shown in FIG. 4, the heat exchanging part 201 has a double passage structure in which a high pressure refrigerant passage 200 a through which the high pressure refrigerant discharged from the gas cooler 100 flows and low pressure refrigerant passages 200 b through which the low pressure refrigerant flows are coaxially formed. The high pressure refrigerant passage 200 a extends along an axis of the heat exchanging part 201 and the low pressure refrigerant passages 200 b are formed on a radial outer side of the high pressure refrigerant passage 200 a.

The internal heat exchanger 200 has the high pressure refrigerant inlet portion 202 and a low pressure refrigerant outlet portion 203 at ends of the heat exchanging part 201. In this embodiment, the heat exchanging part 201 is bent into a U-shape. Thus, the high pressure refrigerant inlet portion 202 and the low pressure refrigerant outlet potion 203 are located adjacent to each other, i.e., on the same side of the heat exchanging part 201.

In this embodiment, the internal heat exchanger 200 is integrated with the gas cooler 100. For example, as shown in FIG. 2, the internal heat exchanger 200 is held by clamps 206 extending from the header tank 140 and the side plate 130 of the gas cooler 100. Here, the clamps 206 hold the heat exchanging part 201 through rubber packing 207.

Further, the internal heat exchanger 200 is arranged in front of the gas cooler 100, i.e., upstream of the gas cooler 100 with respect to the flow of the cooling air. Thus, the cooling air, which has been cooled by the low pressure refrigerant flowing in the low pressure refrigerant passages 200 b of the internal heat exchanger, flows to the gas cooler 100. Preferably, the internal heat exchanger 200 is arranged such that the air that has been cooled by the internal heat exchanger 200 flows adjacent to a last path of the refrigerant flow in the gas cooler 100.

Namely, in the example shown in FIGS. 2 and 3, the gas cooler 100 has one separator 141, and the refrigerant generally flows from the upper tubes 110 toward the lower tubes 110 in a U-turn manner in the gas cooler 100. Thus, the last path of the refrigerant flow corresponds to the flow of refrigerant flowing in the lower tubes 110.

The high pressure refrigerant outlet portion 203 is connected to the decompressing device 300. In this embodiment, the decompressing device 300 is constructed of a capillary-type expansion valve 300A. The expansion valve 300A has a temperature sensing part (temperature sensing tube) 301 outside of its main body. The temperature sensing part 301 is disposed to be in contact with the first refrigerant pipe P1.

The main body of the expansion valve 300A is connected to the high pressure refrigerant outlet portion 203 of the internal heat exchanger 200 beforehand. That is, the main body of the expansion valve 300A is integrated into the component assembly together with the gas cooler 100, the internal heat exchanger 200 and the first refrigerant pipe P1.

In this embodiment, the gas cooler 100 on which the associated components such as the internal heat exchanger 200, the expansion valve 300A, the first refrigerant pipe P1 and the like are integrated beforehand is handled as the component assembly. The component assembly is fixed to an object such as a vehicle body through brackets 701.

The expansion valve 300A isenthalpically decompresses and expands the high pressure refrigerant and controls the pressure of the high pressure refrigerant based on the temperature of the refrigerant discharged from the gas cooler 100. The low pressure refrigerant decompressed in the expansion valve 300A is introduced to the evaporator 400 through a second refrigerant pipe P2, which is for example made of metal. Here, the second refrigerant pipe P2 provides a portion of the low pressure refrigerant passage part.

The evaporator 400 is housed in an air conditioning unit (not shown) mounted in a passenger compartment PC of the vehicle. The evaporator 400 performs heat exchange between the low pressure refrigerant decompressed by the expansion valve 300A and air to be introduced into the passenger compartment, thereby cooling the air with evaporation of the refrigerant.

The evaporator 400 is connected to the accumulator 500 through a third refrigerant pipe P3, which is for example made of metal. Thus, the low pressure refrigerant, which has been evaporated in the evaporator 400, is introduced to the accumulator 500 through the third refrigerant pipe P3. Here, the third refrigerant pipe P3 provides a portion of the low pressure refrigerant passage part.

The accumulator 500 separates the low pressure refrigerant into a gas-phase refrigerant and a liquid-phase refrigerant therein, and accumulates surplus refrigerant therein as the liquid-phase refrigerant. Also, the accumulator 500 supplies the gas-phase refrigerant and refrigerating oil, which has been separated and extracted, toward a suction side of the compressor 10.

In this embodiment, a refrigerant outlet of the accumulator 500 is connected to a low pressure refrigerant inlet portion 204 of the internal heat exchanger 200 through a fourth refrigerant pipe P4, which is for example made of metal. Thus, the gas-phase refrigerant and refrigerating oil is introduced to the low pressure refrigerant inlet portion 204 through the fourth refrigerant pipe P4. Here, the fourth refrigerant pipe P4 provides a portion of the low pressure refrigerant passage part.

The low pressure refrigerant introduced to the low pressure refrigerant inlet portion 204 flows through the low pressure refrigerant passages 200 b toward a low pressure refrigerant outlet portion 205. While flowing through the low pressure refrigerant passages 200 b, the low pressure refrigerant exchanges heat with the high pressure refrigerant flowing in the high pressure refrigerant passage 200 a and the air flowing outside of the heat exchanging part 201 for cooling the high pressure refrigerant and the air.

The low pressure refrigerant discharged from the low pressure refrigerant passages 200 b of the internal heat exchanger 200 is introduced into the compressor 10 through a second refrigerant hose H2 having flexibility. The second refrigerant hose H2 has a metal portion K at its end. The metal portion K is connected to the low pressure refrigerant outlet portion 205 of the internal heat exchanger 200. The metal portion K provides a portion of the low pressure refrigerant passage part.

The metal portion K is located upstream of the gas cooler 100 with respect to the air flow direction, i.e., in front of the gas cooler 100. Preferably, the metal portion K is located adjacent to the last refrigerant path of the gas cooler 100, upstream of the gas cooler 100 with respect to the air flow direction. Thus, the metal portion K enhances to cool the air flowing toward the gas cooler 100. As shown in FIG. 6, a radiator 600 is provided downstream of the gas cooler 100 with respect to the air flow direction.

In this embodiment, the gas cooler 100 provides a substantially U-shaped refrigerant path therein from the inlet joint 191 toward the outlet joint 192. The internal heat exchanger 200 also has a generally U-shape and is arranged upstream of the gas cooler 100 with respect to the air flow direction, i.e., on an air inlet side of the gas cooler 100. Further, the internal heat exchanger 200 is arranged at a position adjacent to a downstream area of the U-shaped refrigerant path along the air inlet side of the gas cooler 100. In other words, the internal heat exchanger 200 is arranged such that the refrigerant inlet and outlet portions 202, 203, 204, 205 are located on the same side as the header tank 140 that has the inlet joint 191 and the outlet joint 192, and the heat exchanging part 201 extends substantially parallel to the core part 101 of the gas cooler 100.

As such, the internal heat exchanger 200 includes a first horizontal portion, a turn portion (vertical portion) and a second horizontal portion. The first horizontal portion extends in a horizontal direction at a position corresponding to a slightly upper portion of the gas cooler 100 that is slightly higher than a middle position of the core part 101 of the gas cooler 100 in a vertical direction. The turn portion extends in a vertical direction along a side of the core part 101 on which the header tank 140 without having the inlet joint 191 and the outlet joint 192 is provided. The second horizontal portion extends in the horizontal direction at a position corresponding to a lower area of the core part 101.

Namely, the internal heat exchanger 200 is mostly located adjacent to the lower area of the core part 101, i.e., the downstream path of the high pressure refrigerant path of the gas cooler 100. In other words, the internal heat exchanger 200 is arranged adjacent to the outlet joint 192 in a concentrated manner.

Further, the low pressure refrigerant inlet portion 204 is arranged higher than the low pressure refrigerant outlet portion 205 in a condition mounted in the vehicle. The internal heat exchanger 200 is fixed by the clamps 206 as the fixing members that are provided on a peripheral portion of the gas cooler 100.

The high pressure refrigerant inlet and outlet portions 202, 203 and the low pressure refrigerant inlet and outlet portions 204, 205 of the internal heat exchanger 200 are located adjacent to the peripheral portion of the gas cooler 100. Further, the high pressure refrigerant inlet and outlet portions 202, 203 and the low pressure refrigerant inlet and outlet portions 204, 205 of the internal heat exchanger 200 and the inlet and outlet joints 191, 192 of the gas cooler 100 are arranged on the same side in the component assembly in a concentrated manner.

Next, effects of this embodiment will be described. The low pressure refrigerant passage part including the internal heat exchanger 200, the metal portion K of the second refrigerant hose H2 and the like is arranged upstream of the gas cooler 100 with respect to the flow of the cooling air. Thus, the cooling air is cooled by the low pressure refrigerant passage part, and then flows into the gas cooler 100.

As such, the temperature of the cooling air to be introduced toward the gas cooler 100 is reduced by the heat exchange with the low pressure refrigerant passage part. Accordingly, the refrigerant flowing in the gas cooler 100 is stably cooled by the cooling air, even when temperature distribution of air affected by type of vehicles and structural differences of front portions of vehicles, and even when arrangement positions of the refrigerant inlet and outlet of the gas cooler 100 are limited.

Inside of the gas cooler 100, the temperature of the refrigerant decreases toward a downstream position of the refrigerant flow as exchanges heat with the cooling air. The low pressure refrigerant passage part is arranged at a position adjacent to the last path of the flow of the high pressure refrigerant of the gas cooler 100, where the temperature of the high pressure refrigerant is reduced. Thus, the area adjacent to the last path of the flow of the high pressure refrigerant is cooled by the cooling air that has been cooled by the low pressure refrigerant passage part. Accordingly, cooling efficiency of the high pressure refrigerant improves.

Further, the internal heat exchanger 200 includes the heat exchanging part 201 having the double passage structure in which the low pressure refrigerant passages 200 b are disposed on the radially outside of the high pressure refrigerant passage 200 a. Since this internal heat exchanger 200 is arranged upstream of the gas cooler 100 with respect to the flow of the cooling air, the cooling air is cooled by the low pressure refrigerant flowing in the low pressure refrigerant passages 200 b.

Also, the second refrigerant hose H2 has the metal portion K as a portion of the low pressure refrigerant passage part. Since this metal portion K is arranged upstream of the gas cooler 100 with respect to the flow of the cooling air, the air is cooled by the low pressure refrigerant flowing in the metal portion K.

The refrigerant discharged from the compressor 10 has a pressure equal to or higher than the critical pressure. Thus, this refrigerating cycle is suitable for the supercritical vapor compression refrigerating cycle. Also, carbon dioxide is used as the refrigerant, since it is easily practiced.

Further, the internal heat exchanger 200 is integrated with the gas cooler 100 as into the component assembly, before mounted to the vehicle. Actually, the gas cooler 100 is a relatively large component of the components for the refrigerating cycle. The internal heat exchanger 200 is integrated with this large gas cooler 100 before mounted to the vehicle. Thus, by fixing the gas cooler 100 to the vehicle, the internal heat exchanger 200 is also mounted to and fixed in the vehicle. In addition to the internal heat exchanger 200, other associated components can be also integrated into the component assembly before mounted to the vehicle.

Accordingly, the internal heat exchanger 260 and the gas cooler 100 are constructed in compact. Further, assemblability of the internal heat exchanger 200 improves. Moreover, the internal heat exchanger 200 and the gas cooler 100 are handled as a single unit, it is easily transported and fixed to the vehicle.

In the above discussion, the internal heat exchanger 200 is integrated with the gas cooler 100 by the clamps 206. However, the internal heat exchanger 200 and other associated components may be integrated with the gas cooler 100 by other ways or means. For example, the internal heat exchanger 200 and the associated components may be integrated with the gas cooler 100 by welding and the like, which provides sufficient connection. As another example, the internal heat exchanger 200 and the associated components may be integrated with the gas cooler 100 by using fixing members such as screws. Further, the internal heat exchanger 200 and the associated components may be integrated with the gas cooler 100 by sharing portions thereof. That is, the portions of the internal heat exchanger 200 or the associated components may be constructed by portions of the gas cooler 100, such as the core part 101 and the header tanks 140.

In a refrigerating cycle shown in FIGS. 8 and 9, the internal heat exchanger 200 is arranged on a rear side of the gas cooler 100 in the engine compartment EC. In this embodiment, on the other hand, the internal heat exchanger 200 is arranged in front of the gas cooler 100. Therefore, spaces on the rear side of the gas cooler 100, where the internal heat exchanger 200 and associated pipes are conventionally arranged as shown in FIGS. 8 and 9, are effectively used for other purposes.

In general, the gas cooler 100 is arranged in front of the radiator 600. In this embodiment, since the internal heat exchanger 200 is arranged in front of the gas cooler 100, pipes are easily coupled in a front part of the vehicle (on a side opposite to the radiator 600 with respect to the gas cooler 100) after the gas cooler 100 is fixed to the vehicle body. Thus, this arrangement improves workability.

The first refrigerant pipe P1 is also integrated into the component assembly. Therefore, the first refrigerant pipe P1 is easily coupled outside of the engine compartment. Also, the number of coupling work in the engine compartment reduces.

Further, the expansion valve 300 is also integrated into the component assembly. Therefore, the decompressing device 300 is easily assembled beforehand outside of the engine compartment. Also, the number of coupling work in the engine compartment reduces.

As described in the above, the internal heat exchanger 200, the first refrigerant pipe P1, and the decompressing device 300 are integrally connected into the component assembly before mounted on the vehicle. The gas cooler 100 has support portions such as frames and clamps 206 for supporting the internal heat exchanger 200 and the like. The gas cooler 100 to which the internal heat exchanger 200, the first refrigerant pipe P1 and the decompressing device 300 are integrated beforehand is fixed to the vehicle body through the brackets 701 that are fixed to the gas cooler 100. In other words, the internal heat exchanger 200, the first refrigerant pipe P1, the decompressing device 300 and the gas cooler 100 share the brackets 701 to be fixed to the vehicle body.

For example, the brackets 701 are fixed to the vehicle body by supporting means such as bolts and hooks. Accordingly, the number of parts such as the brackets and screws, the number of work required for fixing the parts, a space for fixing the parts, and the space required to fix the parts reduce.

In the above embodiment, the internal heat exchanger 200, the decompressing device 300 and the first refrigerant pipe P1 are integrated with the gas cooler 100 as into the component assembly. However, the other components may be also integrated with the component assembly. Alternatively, at least the internal heat exchanger 200 may be integrated with the gas cooler 100 as into the component assembly and fixed to the vehicle body through the brackets 701. Also, the brackets 701 may partly have pin shapes. Also, the component assembly may be fixed to anther object other than the vehicle body.

Also, in the internal heat exchanger 200, the high pressure refrigerant inlet portion 202 and the high pressure refrigerant outlet portions 203 are disposed adjacent to each other. With this arrangement, a portion of a high pressure refrigerant passage through which the high pressure refrigerant flows is disposed adjacent to the decompressing device 300. Therefore, the temperature and/or pressure of the high pressure refrigerant can be detected at a position adjacent to the decompressing device 300, and hence the pressure of the refrigerant is easily controlled in the decompressing device 300.

The shape of the internal heat exchanger 200 is not limited to the U-shape. In a case that the high pressure inlet portion 202 and the high pressure outlet portion 203 are separated from each other, a pipe is coupled to one of the high pressure inlet portion 202 and the high pressure outlet portion 203 and an end of the pipe is arranged at a position adjacent to other one of the high pressure inlet portion 202 and the high pressure outlet portion 203.

In the above embodiment, the decompressing device 300 is constructed of the capillary type expansion valve 300A and has the temperature sensing part 301 on the first refrigerant pipe P1. In the above arrangement, the first refrigerant pipe P1 is located at a suitable position for arranging the temperature sensing part 301. Therefore, the capillary type expansion valve 300A is easily constructed.

Second Embodiment

A second embodiment will be described with reference to FIG. 5. In the second embodiment, the decompressing device 300 is constructed of a box-type expansion valve 300B, instead of the capillary-type expansion valve 300A of the first embodiment. The box-type expansion valve 300B includes a main body that has a first refrigerant passage and a second refrigerant passage therein. The box-type expansion valve 300B includes the temperature sensing part in the first refrigerant passage, and a decompressing part in communication with the second refrigerant passage.

In this embodiment, the expansion valve 300B is disposed such that the high pressure refrigerant, which has been discharged from the gas cooler 100 and flows toward the high pressure refrigerant inlet portion 202 of the internal heat exchanger 200, passes through the first refrigerant passage of the main body. Namely, an inlet of the first refrigerant passage is connected to an end of the first refrigerant pipe P1 and an outlet of the first refrigerant passage is connected to the high pressure refrigerant inlet portion 202 of the internal heat exchanger 200. Also, the high pressure refrigerant, which has been discharged from the high pressure refrigerant passage 200 a of the internal heat exchanger 200 and flows toward the evaporator 400, passes through the second refrigerant passage of the main body to be decompressed by the decompressing part.

Also, the box-type expansion valve 300B may be employed in the refrigerating cycle without having the first refrigerant pipe P1. In this case, the refrigerant passage of the main body is disposed between the outlet joint 192 of the gas cooler 100 and the high pressure refrigerant inlet portion 202 of the internal heat exchanger 200. As such, the box-type expansion valve 300B is easily constructed. Arrangements and structures of the refrigerating cycle other than the above are similar to the first embodiment.

Third Embodiment

A third embodiment will be described with reference to FIGS. 6A and 6B. In this embodiment, the fourth refrigerant pipe P4 is arranged to extend upstream side of the gas cooler 100 with respect to the flow of the cooling air A1, i.e., in front of the gas cooler 100, as the low pressure refrigerant passage part. Preferably, the fourth refrigerant pipe P4 is arranged at the position corresponding to the last path of the refrigerant flow in the gas cooler 100.

The fourth refrigerant pipe P4 is for example made of metal and connected such that the low pressure refrigerant discharged from the accumulator 500 is introduced into the low pressure refrigerant passages 200 b of the internal heat exchanger 200. Since the fourth refrigerant pipe P4 is arranged upstream of the gas cooler 100 with respect to the air flow direction, the air to be introduced toward the gas cooler 100 is cooled by the low pressure refrigerant flowing in the fourth refrigerant pipe P4.

Further, the second refrigerant pipe P2 and the third refrigerant pipe P3 may be partly arranged to extend along the upstream side of the gas cooler 100 with respect to the flow of the cooling fluid, as portions of the low pressure refrigerant passage part. The second refrigerant pipe P2 is for example made of metal and connected such that the low pressure refrigerant decompressed by the decompressing device 300 is introduced into the evaporator 400. The third refrigerant pipe P3 is for example made of metal and connected such that the low pressure refrigerant discharged from the evaporator 400 is introduced into the accumulator 500.

Since at least portions of the second and third refrigerant pipes P2, P3 are arranged upstream of the gas cooler with respect to the flow of the cooling air, the air to be introduced into the gas cooler 100 is cooled by the low pressure refrigerant flowing in the second and third refrigerant pipes P2, P3. Accordingly, the cooling efficiency of the refrigerant improves. FIG. 6B shows an example of arrangement of the low pressure refrigerant passage part on the upstream side of the gas cooler 100 with respect to the flow of air. The arrangement of the low pressure refrigerant passage part may not be limited to the illustrated example, but may be modified various ways.

MODIFICATIONS

In the above embodiments, the refrigerating cycle constructs the supercritical vapor compression refrigerating cycle using carbon dioxide as the refrigerant. However, the present invention is not limited to the above embodiments, but may be used to a subcritical vapor compression refrigerating cycle in which chlorofluorocarbon is used as the refrigerant and a discharge pressure of the compressor is equal to or lower than a critical pressure.

The example embodiments of the present invention are described above. However, the present invention is not limited to the above example embodiment, but may be implemented in other ways without departing from the spirit of the invention. 

1. A refrigerating cycle comprising: a compressor for sucking and compressing a refrigerant; a high pressure heat exchanger for performing heat exchange between a high pressure refrigerant compressed in the compressor and a cooling fluid flowing outside of the high pressure heat exchanger; a decompressing device for decompressing the high pressure refrigerant into a low pressure refrigerant; a low pressure heat exchanger for evaporating the low pressure refrigerant; and a low pressure refrigerant passage part for defining a passage through which the low pressure refrigerant flows, wherein the low pressure refrigerant passage part is disposed at a position upstream of the high pressure heat exchanger with respect to a flow of the cooling fluid such that the cooling fluid is cooled by the low pressure refrigerant passage part before being introduced toward the high pressure heat exchanger.
 2. The refrigerating cycle according to claim 1, wherein the low pressure refrigerant passage part is provided at a position adjacent to a last path of a flow of the high pressure refrigerant in the high pressure heat exchanger.
 3. The refrigerant cycle according to claim 1, wherein the low pressure refrigerant passage part includes an internal heat exchanger that has a high pressure refrigerant passage for allowing the high pressure refrigerant to flow and a low pressure refrigerant passage for allowing the low pressure refrigerant to flow, the low pressure refrigerant passage is disposed on an outer side of the high pressure refrigerant passage within the internal heat exchanger.
 4. The refrigerating cycle according to claim 1, wherein the low pressure refrigerant passage part includes a metal portion of a refrigerant hose for introducing the low pressure refrigerant toward the compressor.
 5. The refrigerating cycle according to claim 1, wherein the low pressure refrigerant passage part includes at least a portion of a second metallic refrigerant pipe for introducing the low pressure refrigerant decompressed in the decompressing device toward the low pressure heat exchanger.
 6. The refrigerating cycle according to claim 1, further comprising: a gas-liquid separator for separating the low pressure refrigerant into a gas-phase refrigerant and a liquid-phase refrigerant, accumulating the liquid-phase refrigerant therein, and discharging the gas-phase refrigerant, wherein the low pressure refrigerant passage part includes at least a portion of a third metallic refrigerant pipe for introducing the low pressure refrigerant discharged from the low pressure heat exchanger toward the gas-liquid separator.
 7. The refrigerating cycle according to claim 1, further comprising: a gas-liquid separator for separating the low pressure refrigerant into a gas-phase refrigerant and a liquid-phase refrigerant, accumulating the liquid-phase refrigerant therein, and discharging the gas-phase refrigerant; and an internal heat exchanger for performing heat exchange between the high pressure refrigerant and the low pressure refrigerant, wherein the low pressure refrigerant passage part includes at least a portion of a fourth metallic refrigerant pipe for introducing the low pressure refrigerant discharged from the gas-liquid separator toward the internal heat exchanger.
 8. The refrigerating cycle according to claim 7, wherein the internal heat exchanger is included in the low pressure refrigerant passage part.
 9. The refrigerating cycle according to claim 1, wherein the high pressure refrigerant has a pressure equal to or higher than a critical pressure.
 10. The refrigerating cycle according to claim 1, wherein the refrigerant is carbon dioxide.
 11. The refrigerating cycle according to claim 1, wherein the low pressure refrigerant passage part and the high pressure heat exchanger are integrated into a unit as a component assembly before being mounted to an object.
 12. A component assembly for a refrigerating cycle, comprising: a high pressure heat exchanger for performing heat exchange between a high pressure refrigerant and a cooling fluid flowing outside of the high pressure heat exchanger; and an internal heat exchanger for performing heat exchange between the high pressure refrigerant and a low pressure refrigerant that has a pressure lower than a pressure of the high pressure refrigerant, wherein the internal heat exchanger is integrated with the high pressure heat exchanger on a first side of the high pressure heat exchanger, the first side corresponding to an upstream side with respect to a flow of the cooling fluid.
 13. The component assembly according to claim 12, further comprising: a first refrigerant pipe for introducing the high pressure refrigerant discharged from the high pressure heat exchanger toward the internal heat exchanger, wherein the first refrigerant pipe is integrated with the high pressure heat exchanger and the internal heat exchanger.
 14. The component assembly according to claim 12, further comprising: a decompressing device for decompressing the high pressure refrigerant, wherein the decompressing device is integrated with at least one of the high pressure heat exchanger and the internal heat exchanger.
 15. The component assembly according to claim 12, further comprising: a bracket to be fixed to an object, wherein the bracket is integrated with at least one of the high pressure heat exchanger and the internal heat exchanger such that the high pressure heat exchanger and the internal heat exchanger share the bracket to be fixed to the object.
 16. The component assembly according to claim 12, wherein the internal heat exchanger has a high pressure refrigerant inlet portion and a high pressure refrigerant outlet portion, and the internal heat exchanger is constructed such that the high pressure refrigerant inlet portion and the high pressure refrigerant outlet portion are located adjacent to each other.
 17. The component assembly according to claim 14, wherein the decompressing device includes a capillary-type expansion valve having a main body and a temperature sensing part outside of the main body, and the temperature sensing part is disposed in contact with the first refrigerant pipe.
 18. The component assembly according to claim 14, wherein the decompressing device includes a box-type expansion valve that has a main body defining a first passageway and a second passageway therein and a temperature sensing part in the first passageway, the box-type expansion valve is disposed such that the high pressure refrigerant that is discharged from the high pressure heat exchanger and flows toward the internal heat exchanger flows through the first passageway. 